﻿Shader "Custom/dissolve" {
	Properties {
		_Tint ("Tint", Color) = (1,1,1,1)
		
		_MainTex ("Albedo (RGB)", 2D) = "white" {}
		_DissolveTex ("DissolveTex" , 2D) = "white" {}
		
		_Step ("Step" ,Range(0,1)) = 0.0
		_Glossiness ("Smoothness", Range(0,1)) = 0.5
		_Metallic ("Metallic", Range(0,1)) = 0.0
		_Bound("Bound", Range(0,1)) = 0.1
		_Intensity("Intensity" ,Range(0,1)) = 0.01
	}
	SubShader {
		Tags { "RenderType"="Opaque" }
		LOD 200
		
		CGPROGRAM
		// Physically based Standard lighting model, and enable shadows on all light types
		#pragma surface surf Standard fullforwardshadows

		// Use shader model 3.0 target, to get nicer looking lighting
		#pragma target 3.0

		sampler2D _MainTex;
		sampler2D _DissolveTex;

		struct Input {
			float2 uv_MainTex;
		};

		half _Glossiness;
		half _Metallic;
		fixed4 _Tint;
		float _Step;
		float _Bound;
		float _Intensity;

		// Add instancing support for this shader. You need to check 'Enable Instancing' on materials that use the shader.
		// See https://docs.unity3d.com/Manual/GPUInstancing.html for more information about instancing.
		// #pragma instancing_options assumeuniformscaling
		UNITY_INSTANCING_CBUFFER_START(Props)
			// put more per-instance properties here
		UNITY_INSTANCING_CBUFFER_END

		void surf (Input IN, inout SurfaceOutputStandard o) {
			// Albedo comes from a texture tinted by color
			fixed4 c = tex2D (_MainTex, IN.uv_MainTex);
			
			fixed4 d = tex2D (_DissolveTex , IN.uv_MainTex);
			
			float mask = d.r - _Step;
			
			if(mask < _Bound){
			    c = c * _Tint * _Intensity / mask;
			}
			
			clip(mask);
			
			o.Albedo = c.rgb;
			// Metallic and smoothness come from slider variables
			o.Metallic = _Metallic;
			o.Smoothness = _Glossiness;
			o.Alpha = c.a;
		}
		ENDCG
	}
	FallBack "Diffuse"
}
